Differential DNA Replication in Drosophila Development

果蝇发育中的差异DNA复制

• 批准号: 8071619
• 负责人: Terry L. ORR-WEAVER
• 金额: $ 39.18万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8071619
• 关键词: Affect; Animals; Binding; Binding Proteins; Binding Sites; Cell Cycle; Cell Differentiation process; Cells; Cellular biology; Collection; DNA; DNA biosynthesis; DNA replication origin; Development; Drosophila genus; E2F transcription factors; Ensure; Factor Analysis; Foundations; Funding; Gene Dosage; Genes; Genetic Transcription; Genomics; Goals; Histone Acetylation; Human; Metastatic to; Methodology; Mitosis; Modeling; Monitor; Movement; Ovarian Follicle; Ploidies; Polyploid Cells; Polyploidy; Process; Protein Binding; Regulation; Replication Origin; Repression; Research; Role; Salivary Glands; Staging; Structure; Tissues; genetic regulatory protein; mutant; protein function; tumor progression

DESCRIPTION (provided by applicant): Control of DNA replication is critical to ensure accurate copy number of genes, because both loss of gene copies and increased copy number by amplification are associated with the onset of cancer and progression to metastatic states. Elucidation of regulatory mechanisms for metazoan DNA replication has been hampered by difficulty in defining specific origins of replication and monitoring their activation. Most animals, including humans, contain polyploid tissues in which the DNA content of the cells is increased by a modified cell cycle, the endo cycle, lacking mitosis. In addition to the overall increase in genomic DNA, in many polyploid cells differential DNA replication occurs in which specific genomic intervals are not replicated or in some cases are over-replicated and amplified. These instances of differential DNA replication provide superb models for elucidating the structure and regulation of metazoan DNA replication origins. Using genomic methodologies, amplified genomic regions were identified in the Drosophila ovarian follicle cells and single copy, euchromatic underreplicated regions were found in the larval salivary gland. The replication origins within the amplified regions are subject to developmental control and permit analysis of the factors responsible for origin activation and repression, as well as discovery of mechanisms by which metazoan DNA replication is initiated. The aims of this research are to exploit these Drosophila replication models to define the mechanisms that activate initiation at the origins during follicle cell differentiation, to determine how replication origins are inactivated and to use mutants to identify new regulatory proteins, and to analyze mechanisms controlling replication fork progression. The identification of defined replication origins whose duplication can be quantified, the ability to detect replication proteins bound at these origins and moving with the replication forks, combined with a collection of mutants affecting these processes permits these experimental goals to be achieved.

描述(申请人提供)：控制DNA复制对于确保准确的基因拷贝数至关重要，因为基因拷贝的丢失和通过扩增而增加的拷贝数都与癌症的发生和向转移状态的进展有关。后生动物DNA复制的调控机制的阐明一直受到定义复制的特定起点和监测其激活的困难。大多数动物，包括人类，都含有多倍体组织，在多倍体组织中，细胞的DNA含量通过修改后的细胞周期--内切周期--增加，但缺乏有丝分裂。除了基因组DNA的总体增加外，在许多多倍体细胞中，还会发生差异DNA复制，其中特定的基因组间隔不被复制，或者在某些情况下过度复制和扩增。这些差异DNA复制的实例为阐明后生动物DNA复制起点的结构和调控提供了极好的模型。利用基因组学方法，在果蝇卵巢滤泡细胞中发现了扩增的基因组区域，在幼虫唾液腺中发现了单拷贝、常染色质复制不足的区域。扩增区域内的复制起始点受到发育控制，并允许分析负责起始点激活和抑制的因素，以及发现启动后生动物DNA复制的机制。本研究的目的是利用这些果蝇复制模型来确定在毛囊细胞分化过程中激活起始点的机制，确定复制起始点是如何失活的，并利用突变来识别新的调节蛋白，并分析控制复制分叉进展的机制。识别可量化其复制的已定义复制源，能够检测 复制蛋白结合在这些起点上，并与复制叉子一起移动，与一系列影响这些过程的突变体结合在一起，使这些实验目标得以实现。